1. Field of the Invention
The present invention relates to an apparatus for wave energy harnessing and, particularly, to an apparatus providing a buoyant unit and at least one transmission shaft, with the at least one transmission shaft being actuated by vertical movement of the buoyant unit to harness wave energy.
2. Description of the Related Art
A conventional apparatus for wave energy harnessing, as described in Taiwanese Patent Publication No. 547434, entitled “WAVE ENERGY BOAT”, is installed on a boat body and includes a buoyant unit and a gearing mechanism. A rack member and a plurality of slide shafts are provided on the buoyant unit, with the rack member engaging with the gearing mechanism. Each of the slide shafts is slidably received in a sleeve member such that the slide shafts can guide vertical movement of the buoyant unit.
The gearing mechanism includes a plurality of driving gears, a plurality of driven gears and a transmission shaft. Once assembled, the driving gears and the driven gears are mechanically engaged with each other. Furthermore, the driving gears are mechanically engaged with the rack member of the buoyant unit so that the vertical movement, which may include upward and downward movements, of the buoyant unit can rotate the transmission shaft in the same direction. When the boat body is disposed in water, waves of the water can cause a certain extent of vertical reciprocation of the buoyant unit for operating the apparatus.
In operation, any upward or downward movement of the buoyant unit can cause rotational movement of the transmission shaft via the gearing mechanism so that wave energy is converted into mechanical energy. In this case, the transmission shaft may further mechanically connect with a power generator and a battery device. Accordingly, mechanical energy is converted into electric energy and stored in the battery device.
Generally, a number of design limitations exist for this conventional power generating apparatus due to its complicated structure in manufacturing and problematic aspects which naturally occur during use. With regard to the manufacture of such a complicated structure of the gearing mechanism, the arrangement of the driving and driven gears is complicated and subject to limitations in assembly and maintenance.
Another problem with the operation of the buoyant unit is due to the fact that four of the slide shafts are arranged at four corners of the buoyant float unit. In reciprocating operation, there are inconsistent movements among the four slide shafts that may affect the movement of the buoyant unit. Disadvantageously, the slide shafts and the sleeve members thereof are susceptible to distortion and loss in function after long-term use.
Another problem with the operation of the power generating apparatus is due to the fact that the entire apparatus is installed on the boat body. Accordingly, the boat body and the buoyant unit move synchronously in the same direction, which may cause loss of efficiency of the movement of the buoyant unit. In other words, there is a limitation existing for the distance of the movement of the buoyant unit. In addition to the mentioned disadvantage, electricity generated from the power generating apparatus can only be stored in its battery device and cannot directly be transmitted to a power station or power distribution system. Hence, there is a need for improving such a mobile structure of the apparatus.